Friday, June 27

Eric Angelini recently posted to the Sequence Fanatics discussion list a very nice 1, 2, 3, 5, 11, 12, 4, 8, 7, ... which ended up as A243357: The lexicographically earliest sequence (not reusing any terms) with the property that if a vertical line is drawn between any pair of adjacent digits (commas and spaces excluded), the number Z formed by the digits to the left of the line is divisible by the final digit of Z. So, a line not just between the terms 3 and 5 (say), or the term 5 and the 1 of the following 11, but also between the two ones of that 11. To wit:

Most obviously, any number containing a zero digit will have been excluded because division by zero is a no-no. Let's call this reason #1. We can exclude from A244033 those numbers that fail because of reason #1. What remains ended up as A244034:

Why do these numbers fail to be included in A243357? Examining the initial ten terms, one realizes soon enough that multiples of 4 ending in 4 and multiples of 8 ending in 8 will always have an even digit preceding the 4 or 8. Therefore 14, 18, 34, 38, 54, 58, 74, 78, 94, 98, or any larger number containing these as a substring, will have been excluded for that reason. Let's call this reason #2. We can exclude from A244034 those numbers that fail because of reason #2. What remains is:

Why do these numbers fail to be included in A243357? Not because of reason #1. Not because of reason #2. You can see where I'm going with this. Without further ado, I present reasons to exclude from A243357 certain numbers:

#1: numbers containing one or more of the single-digit 0.

#2: numbers containing as a substring any one or more of the 2-digit strings 14, 18, 34, 38, 54, 58, 74, 78, 94, 98.

And so on. Obviously, numbers may fail to be included in A243357 for more than one reason. For example, 140 fails because of reason #1 and reason #2. The numbers in each reason are a kind of puzzle asking you to determine why that number fails. Once the eight integers ending with 8 in reason #3 are dispensed with, it appears that every other number involves some sort of division complication of integers beginning and ending with 3, 6, or 9, or beginning and ending with 7.

Thursday, June 26

I'm coming up to five months usage of my Mac Pro. I long ago disconnected it from the living room TV and placed it on the high plateau at the back of my rolltop desk, hidden from view for the most part by my iMac. I am happily using wireless screen sharing to interact with it but I did order a ThunderBolt cable so that I might do so directly via Target Display Mode.

The screen grab shows what I am doing on my Pro. On the top left is Mathematica calculating an extension to A066364, something I have been working on for quite a while. I'm near 2000 terms and I have another two weeks to go before I reach 10^12. Below Mathematica is my Activity Monitor showing the top active processes. My Pro has only six cores but through some sort of doubling magic the sum of all processes can approach 1200% CPU. At bottom center is my dock, and behind it my Terminal window which I use only to run Dario Alpern's java factorization app. In fact, I have nine of these running (top and right) working on 120-digit composites. The seventh one, just above the Terminal, has found a 42-digit factor (highlighted in blue). Bottom right is a hint of my Finder/desktop.

Friday, June 13

When I initially wrote my last item about the funeral of Josephine Powers Agen, I had indicated that David Powers Sr was born ~1824, and his wife Julia Callahan, ~1826. Those dates are direct conversions from their newspaper death notices (in 1886 and 1884) of ages 62 and 58, respectively. There's always that issue of the next birthday anniversary being up-and-coming (say, in the following month) which might skew the year but the greater problem is if the reported ages actually portray any semblance of reality.

Within twelve hours of publishing that blog entry, I discovered a previously-unknown-to-me 1855 Sandy Creek NY census that in all likelihood contained our two protagonists. Julia's surname of Callahan comes from David Powers Jr's 1929 death registration wherein his parents are named. FamilySearch suggests Kallegan is the 1855 transcription of Julia's surname although, looking at the script, it might just as well be Kalligan. There's even a hint of an h in there — if that isn't an extraneous mark:

But I'm more interested in Julia's age as a means of verifying that this is our Julia Callahan. The 24 would make her birth year ~1831, five years off; not a very good fit. So why would I think that this is her? Apart from being in the right place, it's the presence in this census' family unit of an Edward Powers. Edward is noted as being in that location for only two months (compared to Julia's two years). We do not know when David Powers Sr married Julia Callahan but their first child, David Edward, was born 7 February 1857 in Sandy Creek NY, so conceived in April or May 1856. The date of the census is 8 June 1855, so Edward arrived there in March 1855. About a year to get to know and marry Julia and, nine months later, name his first-born son after himself: David Edward Powers.

If Edward is David Sr, the age of 23 would make his birth year ~1832, eight years off; an even worse fit than Julia's. Fortunately, we have both David and Julia in other censuses: 1860, 1870, 1875, and 1880.

The 1855 ages actually agree quite well with the 1860 ones. The 1870 ages appear to be ten years off suggesting a possible subtraction mistake — were it not for the continuation of the age inflation in subsequent censuses and reports at death.

As a result of contemplating all this, I edited the Josephine Agen blog entry by removing David and Julia's birth years. Much as I give credence, generally, to ages reported at death, in my database I am making their birth years 1832 and 1831, respectively, in agreement with the earlier censuses. This would make them only 54 and 53, respectively, when they died.

Tuesday, June 10

The chart shows what I currently know about the shoots of my wife's Powers ancestry. At the top are David Edward Powers (1857-1929) and Agnes Sullivan (1857-1936), her great-grandparents. David Edward's parents, David Powers Sr (died 1886) and Julia Callahan (died 1884) were alone at the root of the tree until March 2011, when my research associates and I discovered a sibling for David: Michael Powers (1845-1918) with wife Mary Brady (1847-1886).

Michael's eldest child, Josephine, died 22 Dec 1920 and the funeral was held two days later. A Christmas eve Utica Herald-Dispatch report named the pallbearers: John Daunt of Lacona, J.S. Powers of Watertown, James B. McIntosh of Albany, James and John Powers of Utica, Edward F. Dunn of Whitesboro. Five of the six names are in the chart and provide a wonderful means to tie the family units together. But who was James Powers of Utica?

Subsequent searches failed to identify such a family member, much as we might have liked to discover yet another branch in the tree. My best guess is that the newspaper put James and John together because they were both from Utica and then (for an unknown reason) omitted James' surname. So, probably, James Powers was in fact James E. Costello, whose family is the most likely of the three that are without a pallbearer representative to have contributed one.